Well packer and releasable latch for hook wall means



Dec. 15, 1959 A. E, LEVENDOSKI WELL PACKER AND RELEASABLE LATCH FOR HOOKWALL MEANS 2 Sheets-Sheet 1 Filed May 21, 1957 A fro/m5 r A. E.LEVENDOSKI 2,917,114

WELL PACKER AND RELEASABLE LATCH FOR HOOK WALL mans Filed may 21.

Dec. 15, 1959 2 Sheetg-Sh'eet 2 INVENTOR.

A woe/m United States Patent WELL PACKER AND RELEASABLE LATCH FOR HOOKWALL MEAN S Alfred E. Levendoski, Depew, N.Y., assignor to American Iron& Machine Works Company, Inc., Oklahoma City, Okla., a corporation ofDelaware Application May 21, 1957, Serial No.'660,611 4 Claims. (Cl.166- 139) This invention pertains to a releasable latching de vice, andmore particularly to such a devicefor 'releasably holding in unsetposition the slips of a hookwall means used to holdan apparatus,especially a well packer, in position in a well, and to a well packerembodying such a device.

An object of the invention is to providesuch a device which is quick andcertain in itsoperation, both in movement to and from latched positionandwhile in latched out motion relative to the mandrel axis and arespring biased inwardly, the threads of both mandrel and nut being ofbuttress form wherebyrelative axial movement of the mandrel and nut ispossible in one direction with the nut ratcheting overthe thread but isprevented in the other direction except upon relative rotation tounscrew the nut from the mandrel. Similar devices have been usedpreviously to lock packers and their hookwall means in unset position,but the subject invention has the advantages of faster, surer operationcoupled with'economy of manufacture.

For a description of a preferred embodiment of the invention referencewill be made to the accompanying drawing wherein:

Figure 1 is an elevation, partly in section, showing a well packerembodying the invention, the latching device thereof being in theunlocked or free position and the packer sleeve and hookwall meansthereof beingset;

Figure 2 is a view similar to Figure 1 showing the latching device inthe'locked or active position, both the packer sleeve and itshookwall'means being. unset;

Figure 3 is a view partly in elevation and partly in section, drawn to alarger scale than Figures 1 and 2, showing the latching device used inthe well packer of Figures 1 and 2;

Figure 4' is a top view of the latching device shown in Figure 3, beinga section on line 4-4 of Figure 3, and

Figure 5 is a section on line 55 of Figure 3.

Referring'now to both Figures 1 and 2, there is shown a well packerdisposed in the casing 10 of a well. The well packer comprises alatching mandrel including a tube 11 upset at its lower end at 12(see'Figure 2) to provide a threaded pin 13. The latching mandrelfurther includes a sleeve 14 which is slipped over the other end of thetube and'welded to the tube at 15. The sleeve thereof. The upper end ofmandrel 22 (see Figure 2) is provided interiorly with a threaded socket23' for connection to a string of tubing or the like and is exteriorlygrooved at 24 to facilitate engagement of the apparatus with anovershotin case it has to be fished out of the well.

Slidably disposed on tube 11 below packer expander cone 23 is a slipexpander cone 30 to the upper end of which, as shown in Figure l, isfastened a packer sleeve 31 made of oil resistant rubber-like material.As shown in Figure 1 the packer sleeve has been expanded by entrancetherein of the packer expander cone 23, the packer sleeve being expandedinto sealing engagement with thecasing. In'the Figure 2 position thepacker expander cone 23 is withdrawn from the packer sleeve; Even in theFigure 1 position the packer expander cone does not enter the packersleeve far enough for flange 32 at the upper end of the cone 23 tocontact cuif ring 33 at the upper end of the packer sleeve. Flange 32and cuff ring 33 are useful in protecting the packer sleeve when it isbeing raised in the well casing, especially through'collars. The motionof the expander cone 23 into the packer sleeve is limited by its lowerend contacting clamp ring 34 at the lower end of the packer sleeve, andin this position the internal diameter of cuff ring 33 is at least aslarge as that of the adjacent part of the expander cone 23.

Secured to tube 11 above threaded sleeve 14- are a plurality of stops 40azimuthally spaced around the tube. As shown in Figure 2, these stopsare engageable with a drive ring 41 which'is connected to the lower endof sleeve 42 extending down from the lower end of slip expander cone3%). Stops 40 thus limit relative motion in one direction of the tube 11and the packer sleeve assembly comprising the packer sleeve and slipexpander cone.

' A plurality of hookwall slips 45 are connected to the slip expandercone by dovetail tongues 46 extending out from flatsides of the coneinto dovetail grooves 47 on the flat inner walls of the slips. The slipsare also con nected by double pivoted links 48 to slip ring 49 which "isSlidably-mounted on sleeve 42. A plurality of easing engaging bowsprings are connected 'at their upper ends "to the slip ring 49* and attheir lower ends to the outer portion of a latching device 60, the innerportion of which includes the threaded sleeve 14 with which it is inengagement in Figure 2. Engagement ofslip ring-49 with drive ring- 41,as is also shown in Figure 2, limits downward motion relative to thepacker assembly of the slip assembly comprising the slips, links, slipring, and

bow springs.

In the Figure 2 position the slip assembly is held by the latchingdevice against axial movement relative to the tube. The packer sleeveassembly isheld against such axial movement by engagement of its drivering 41 between stops id and slip ring 49. In this position the slipsare in their retracted position and the packer sleeve is in its relaxedor unexpanded condition, and since the parts areheld against relativeaxial movement in either direction the packer can be lowered or raisedin the well without the packer sleeve or hookwall slips setting.

As will be explained hereinafter, the latching device 60 can be freed byrotation of the tube 11, the bow springs of the slip assembly holdingthe outer or nut portion of the device stationary whilethe innerthreaded portion 14 is unscrewed therefrom. Thereafter downward motionof the tube does not cause the slip assembly to move downwardly, thelatter being held stationary by the bow springs-frictionally engagingthe casing. At this point the packer sleeve assembly, comprising thepacker sleeve and slip expander cone, lies between the downwardlyrmovingpacker expander cone thereabove and the stationary slips therebelow. Thepacker sleeve assembly first moves down with the packer expander cone tocause the slip expander cone to move the slips radially out- Wardly intogripping engagement with the well casingx Then, after the slips are thusset, further downward mo: tion of the packer expander cone expands thepacker sleeve radially outwardly into sealing engagement with thecasing. This is the Figure 1 position.

When it is desired to remove the well packer from the well, or positionit at a diflerent level therein, the tubing string is lifted to withdrawthe packer expander cone from the packer sleeve. Further upward motionof the tubing string causes stops 40 to engage drive ring 41 and liftthe packer sleeve assembly. Upward motion of the packer sleeve assemblycauses the slip expander cone to be withdrawn from the slips and toretract them, the slips being held against upward movement by the bowsprings. Finally, drive ring 41 of the packer sleeve assembly engagesslip ring 49 of the slip assembly and the slip assembly too movesupwardly. At the same time the nut of the latching device ratchetsaxially over the threaded sleeve 14, as will be next explained, and thepacker is again inthe Figure 1 position ready to be moved to the desirednew location.

Referring now particularly to Figures 35, there are shown the details ofthe latching device 60. As previously stated this device is of the typecomprising a threaded mandrel and a segmental nut. The threaded mandrelcomprises tube 11 and sleeve 14 welded thereto at 15. This portion ofthe latching device therefore moves with tube 11. The nut of thelatching device, as previously stated, is connected to the bow springsof the slip assembly and therefore moves with the slips. In theimmediately following portion of the description the two parts of thelatching device, the threaded mandrel and the nut, will sometimes bereferred to as the tube portion and the slip portion to emphasize theirrelationship to the rest of the well packer.

The nut or slip portion of the latching device, that is,

the portion moving with the slips, includes an annular housingcomprising a thick sleeve 61 and a cap 62. The minimum inner diameter ofthe sleeve is larger than the outer diameter of the upset 12 on the tubeand slightly larger than the crest diameter of the threads 16 so that itcan be assembled by slipping it over the upset end of the tube 11. Itcould not be put on from the other end because of interference by stops40 welded onto the tube. The cap 62, on the other hand, has a minimuminner diameter that is too small to pass over threads 16 so that it mustbe placed on the tube from the other end and is provided with notches 63to pass over the stops. The cap is fastened to the sleeve by means ofscrews 64.

The exterior of the sleeve 61 and cap 62 are shaped to provide channels70 to allow drilling mud or other well fluid to pass by the housing. Theexterior of the sleeve is also provided with recesses 71 and the cap iscut back at 71' to receive the lower ends of springs 50 which aresecured therein by screws 72.

Interiorly the sleeve 61 is provided with slots 73 of rectangular crosssection whose bottoms or outermost walls 74 are inclined, flaringupwardly from the tube axis. In each of the several slots 73 is slidablydisposed a pawl 75 having a body of generally rectangular cross sectioncorrelative to the slot section. The outermost or back sides 76 of thepawls taper toward the bottoms of the pawls correlative to theinclination of the flaring back walls of the slots. The faces orinnermost sides of the pawls are provided with thread segments 77correlative to threads 16. The pawls are limited in their downwardtravel, when not engaged with threads 16, by the lower end 78 of thesleeve 61. The cutting of slots 73 so as to leave end 78 intact isfacilitated by first cutting annular groove 79 in the sleeve.

The pawls are guided at their sides by the sides of the slots and areadditionally guided and prevented from falling radially inwardly out ofthe slots by means of guide rods 80. The guide rods pass through holes81 in the pawls. The guide rods are angularly disposed relative to thetube axis and are parallel to the back walls of the slots. The guiderods are held in position by being soldered into cap 62 at their upperends. Helical compression springs 82 concentric with guide rods urge orbias the pawls downwardly and inwardly. The upper ends of the springsbear against cap 62 and the lower ends are received in recesses 83 inthe pawls.

The spring mounted pawls may be said to constitute a segmented nutengageable with the threaded mandrel constituted by tube 11 and threadedsleeve 14.

In operation, when the nut or slip portion of the latching device movesdown relative to the threaded mandrel or tube portion of the latchingdevice, its threaded segments ratchet over the thread 16, the segmentsor pawls moving up and out against the pressure of springs 82 while thethreads 77 pass over threads 16. Then the springs push the pawls downand in to engage the threads 77 beneath threads 16. Motion of the nut inthe opposite direction is then prevented by the fact that the engagedflanks 90, 91 of the mandrel thread and nut thread, respectively, are ofsuch angle to the tube axis, e.g. perpendicular thereto, that axialpressure between the thread flanks does not create any force componenttending to move the pawls radially outwardly, or if such force componentis created it is insufiicient to overcome the sliding friction betweenthe thread faces and the pressure of springs 82. The latching device canthen be separated only by unscrewing the nut from the mandrel. Suchseparation is therefore not eifected by the axial motion of the wellpacker required to lower it or raise it to the desired level. Howeverwhen such separation is desired it can be accomplished quickly by virtueof the triple thread which reduces the number of turns required torelease the latching device.

By virtue of the guide channels 73, the pawls are prevented from turningout of position such that their threads would be crossed relative to thethreads 16 which would prevent reengagement of the latching device. Thisis a very important feature for the device must operate satisfactorilyat the end of a string of pipe which may extend several thousand feetdown into the ground in the presence of a mixture of many fluids andassorted solids. Failure to operate would mean that the pipe would haveto be withdrawn from the well, an operation taking many hours or even awhole day and costing considerable money.

By virtue of the guide rods the pawls are retained in the guidec'hannels'and are additionally guided to prevent their becoming cockedand wedged in the channels which might keep them from returning to theirinnermost position under spring pressure.

Viewed in another light, the pawls may be said to be guided along theaxis of the guide rods in the in and out motion of the pawls and thepawls are prevented from rotating on the guide rods by engagement of thesides of the pawls with the guide channels. However viewed, the guidechannels cooperate with the guide rods to provide a reliable control ofthe motion of the pawls. I While a preferred embodiment of the inventionhas been shown and described, many modifications thereof can be made byone skilled in the art without departing from the spirit of theinvention and it is desired to protect by Letters Patent all forms ofthe invention falling within the scope of the following claims.

I claim:

1. A well packer comprising a tube upset at its lower end and exteriorlythreaded at said end, a sleeve having a smaller inner diameter than theouter diameter of the upset end of said tube and disposed around thetube and fastened to the tube near its lower end, said sleeve having abuttress type thread thereon with its steep flank on the lower side, aplurality of azimuthally spaced t ps eemed to said tube above saidsleeve and spaced,

therefrom, means cooperable with said threaded sleeve to act as areleasable latch including a housing formed of a sleeve and a cap, saidhousing sleeve having a minimum inner diameter larger than the outerdiameter of said upset end of the tube and larger than the outerdiameter of said threaded sleeve, said cap having a minimum innerdiameter smaller than the outer diameter of said threaded sleeve butlarger than the outer diameter of the tube at its upper end, said caphaving notches therein azimuthally spaced apart correlative to thespacing of said stops and larger than said stops, said cap beingfastened to the upper end of said housing sleeve, spring biased pawlmeans in said housing for engaging said threaded sleeve after ratchetingaxially down over the threaded sleeve to prevent upward movement of thehousing relative to the threaded sleeve except when accompanied byrelative rotation thereof, a packer sleeve assembly including a packersleeve and a downwardly converging slip expander connected to the bottomof the packer sleeve, said packer sleeve assembly being slidably mountedon said tube above said stops, a packer expander means connected to saidtube at the upper end thereof, means connected to said packer expandermeans for connection with a well pipe, a slip assembly connected to saidhousing and including a plurality of slips slidably dovetailed to saidslip expander and including further means to frictionally engage with awell casing to tend to prevent motion of said slips relative to suchcasing, and means limiting downward movement of said slip assemblyrelative to said packer assembly, the distances between said packerexpander means and said stops and said threaded sleeve being such thatwhen said pawls in said housing are engaged with said threaded sleevesaid packer sleeve assembly is engaged with said stops and said slipassembly is in its lowermost position relative to said slip expanderdrawing said slips away from casing engaging position and said packerexpander means is withdrawn relative to said packer sleeve which isrelaxed.

2. The combination of claim 1 in which the spring biased pawl means inthe housing comprises a plurality of pawls having thread segments ontheir inner faces correlative to those on the threaded sleeve, the backsof the pawls being tapered downwardly, the housing sleeve has slotstherein correlative to the shape of the pawls, guide rods secured to thecap and disposed one in each slot parallel to the back wall thereof passthrough holes in the pawls parallel to the back faces of the pawls, andhelical compression springs disposed one concentric with each guide rodbear against the cap at their upper ends and are received in recesses inthe tops of the pawls.

3. A latching device comprising an exteriorly threaded mandrel and asegmental nut engageable therewith, said nut including a housing havinga plurality of slots therein, a pawl member received in each slot andhaving means on its inner face for engaging said threaded mandrel toprevent relative axial movement therebetween in one direction exceptwhen the nut is rotated, a guide rod in each slot passing through thepawl member, and means biasing each pawl toward said threaded member.

4. The combination of claim 3 in which said housing comprises a sleeve,said slots in the housing extending from the top of the sleeve part wayto the bottom thereof, and a cap connected to the top of said sleeveclosing said slots, said guide rods being secured to said cap, saidbiasing means including a helical compression spring around each guiderod hearing at its upper end against the cap and at its lower endagainst the pawl member in the corresponding slot.

References Cited in the file of this patent UNITED STATES PATENTS1,098,265 James May 26, 1914 1,593,909 Nixon July 27, 1926 2,205,748Knox June 25, 1940 2,352,423 Church June 27, 1944 2,632,514 FitzpatrickMar. 24, 1953 2,769,499 McKissick Nov. 6, 1956

